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#830832 11/23/20 10:46 pm
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Looking for inputs on what I am thinking. I have set of 7017- 7016 cams that are like new and a set of R tappets. From reading to much I cant use R tappets with the intake? I have a 3134 intake thats in good shape that will work with R tappets so I was thinking about mixing 3134 with 7016. I cant find a good spec on the 7016 cam lift/duration etc. So any inputs would be greatly appreciated. Thanks

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Thats what I use in several bikes including race motors. I do use R lifters and it works fine. I would ask whoever regrinds the lifters for you to ease the leading and following edges of the lifters just a little on the intake side. Seems the 7017 is actually a stock 650 (3134) grind so if it were me and I had a good later nitrided ex cam I would use it and just get a 750 intake. If you're using this as a desert sled, time the cams at 100-101 LC intake and 104 ish ex. for good low end power without giving up much at higher revs.

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[quote=Mike Baker]Thats what I use in several bikes including race motors. I do use R lifters and it works fine.]
So your saying I can use the R lifter with 7016 intake cam just taper leading edge? Yes I am using in for the desert sled project so Wouldn't mind losing a little on top. Do you know if this is the correct factory specs for the 750 cams.intake .350 lift/lobe center 111.5/duration .278 @20 open 26.5-close 69.5
exhaust.350/103LC/.278 open 61.5 close 35.5
Thanks Jeff

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What Mike suggests for lobe centerlines will work well. Don't be concerned about opening and closing specs.....


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Originally Posted by Idaho desert rat
Do you know if this is the correct factory specs for the 750 cams.intake .350 lift/lobe center 111.5/duration .278 @20 open 26.5-close 69.5exhaust.350/103LC/.278 open 61.5 close 35.5
Thanks Jeff

That's about right for the 70-7016 750 intake but the 70-7017 750 exhaust is much milder than those specs. Probably around .300" lift at the cam and 255° duration at 0.020" lift.

Eric


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As Eric says, the 7017 exhaust cam is much milder than the 3134 profile, which in turn is much milder than the 7016 inlet - quite a fierce cam which works very nicely with a 3134 profile exhaust. 70-9989 is commonly available here in UK and that's the same as the 3134 profile. Makes a LOT of difference to torque and gives a bit of an boost to top end too.


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There is a 7017R exhaust cam which has the same profile as the 7016 inlet cam - some of the 'special' cams on the market don;t give such a hot combination as these.

As for followers, I've used R profile followers with the 7016 inlet cams with no problems


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Originally Posted by Tigernuts
There is a 7017R exhaust cam which has the same profile as the 7016 inlet cam - some of the 'special' cams on the market don;t give such a hot combination as these.

The 7017R "spitfire" cam is what I have in my 750, along with the stock intake. Timing specs are essentially what Mike Baker posted up the thread a bit. With decent compression, a set of mikuni flat slides, and a good exhaust, it makes for a great running bike.

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Some blokes made up spinners and ran the 7016 in the exhaust as well
similar to Norish (Weslake) Z-profile.
The better exhaust cam to use with the 7016 was the 4220, but they are hens teeth now.
George Hopwood may have some though. (Hoppybikes) He did the pukka Thruxton stuff.

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Bike Vice- so the 7017 is actually a stock 750 ex grind? I will stand corrected.
Idaho- ease the leading and following edges slightly. I have noticed a bit of wear there in my race bike.

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Thanks guys for the inputs. The 7017 cam is definitely less lift I measured with my calipers .310 vs. the 7016 @ .340.
So looks like the 7016/7017 combo should work fine for me. If I wanted to give up top end to make it pull hard down low where would I set lobe centers?
So with this cam and open exhaust this thing should sound like a beast!!


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